[clang-tools-extra] [clang-tidy] (PR #99713)

via cfe-commits cfe-commits at lists.llvm.org
Fri Jul 19 14:46:23 PDT 2024


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tidy

Author: NagaChaitanya Vellanki (chaitanyav)

<details>
<summary>Changes</summary>

  modernize-use-cpp-style-comments check finds C style comments
  and suggests to use C++ style comments

  Fixes #<!-- -->24841



@<!-- -->LegalizeAdulthood @<!-- -->PiotrZSL 


```
~/scratch/llvm_test_ground/test1.cpp:1:1: warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]
    1 | /* Hello world
      | ^~~~~~~~~~~~~~
    2 |  * this is a line
      |  ~~~~~~~~~~~~~~~~
    3 |  */
      |  ~~
~/scratch/llvm_test_ground/test1.cpp:4:1: warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]
    4 | /*!
      | ^~~
    5 |  * ... text ...
      |  ~~~~~~~~~~~~~~
    6 | */
      | ~~
~/scratch/llvm_test_ground/test1.cpp:7:1: warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]
    7 | /*foo bar goo
      | ^~~~~~~~~~~~~
    8 |  *foo bar goo
      |  ~~~~~~~~~~~~
    9 |  */
      |  ~~
~/scratch/llvm_test_ground/test1.cpp:11:1: warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]
   11 | /*#########################################################
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   12 |  * Fancy comment goes here
      |  ~~~~~~~~~~~~~~~~~~~~~~~~~
   13 |  *#########################################################
      |  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   14 |  */
      |  ~~
~/scratch/llvm_test_ground/test1.cpp:22:34: warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]
   22 |   memcpy(a, b, sizeof(int) * 5); /* Fix me later */
      |                                  ^~~~~~~~~~~~~~~~~~                     
```

---
Full diff: https://github.com/llvm/llvm-project/pull/99713.diff


7 Files Affected:

- (modified) clang-tools-extra/clang-tidy/modernize/CMakeLists.txt (+1) 
- (modified) clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp (+3) 
- (added) clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.cpp (+66) 
- (added) clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.h (+38) 
- (modified) clang-tools-extra/docs/ReleaseNotes.rst (+5) 
- (added) clang-tools-extra/docs/clang-tidy/checks/modernize/use-cpp-style-comments.rst (+12) 
- (added) clang-tools-extra/test/clang-tidy/checkers/modernize/use-cpp-style-comments.cpp (+16) 


``````````diff
diff --git a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
index 4f68c487cac9d..04a1d04cc333e 100644
--- a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
@@ -31,6 +31,7 @@ add_clang_library(clangTidyModernizeModule
   UseAutoCheck.cpp
   UseBoolLiteralsCheck.cpp
   UseConstraintsCheck.cpp
+  UseCppStyleCommentsCheck.cpp
   UseDefaultMemberInitCheck.cpp
   UseDesignatedInitializersCheck.cpp
   UseEmplaceCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
index 1860759332063..39995a32133b3 100644
--- a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
@@ -32,6 +32,7 @@
 #include "UseAutoCheck.h"
 #include "UseBoolLiteralsCheck.h"
 #include "UseConstraintsCheck.h"
+#include "UseCppStyleCommentsCheck.h"
 #include "UseDefaultMemberInitCheck.h"
 #include "UseDesignatedInitializersCheck.h"
 #include "UseEmplaceCheck.h"
@@ -104,6 +105,8 @@ class ModernizeModule : public ClangTidyModule {
         "modernize-use-bool-literals");
     CheckFactories.registerCheck<UseConstraintsCheck>(
         "modernize-use-constraints");
+    CheckFactories.registerCheck<UseCppStyleCommentsCheck>(
+        "modernize-use-cpp-style-comments");
     CheckFactories.registerCheck<UseDefaultMemberInitCheck>(
         "modernize-use-default-member-init");
     CheckFactories.registerCheck<UseEmplaceCheck>("modernize-use-emplace");
diff --git a/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.cpp
new file mode 100644
index 0000000000000..f4d3bbce9f121
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.cpp
@@ -0,0 +1,66 @@
+//===--- UseCppStyleCommentsCheck.cpp - clang-tidy-----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "UseCppStyleCommentsCheck.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Lex/Preprocessor.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::modernize {
+
+class UseCppStyleCommentsCheck::CStyleCommentHandler : public CommentHandler {
+public:
+  CStyleCommentHandler(UseCppStyleCommentsCheck &Check)
+      : Check(Check),
+        CStyleCommentMatch(
+            "^[ \t]*/\\*+[ \t\n]*(.*[ \t\n]*)*[ \t\n]*\\*+/[ \t\n]*$") {}
+
+  bool HandleComment(Preprocessor &PP, SourceRange Range) override {
+
+    if (Range.getBegin().isMacroID() ||
+        PP.getSourceManager().isInSystemHeader(Range.getBegin()))
+      return false;
+
+    const StringRef Text =
+        Lexer::getSourceText(CharSourceRange::getCharRange(Range),
+                             PP.getSourceManager(), PP.getLangOpts());
+
+    SmallVector<StringRef> Matches;
+    if (!CStyleCommentMatch.match(Text, &Matches)) {
+      return false;
+    }
+
+    Check.diag(
+        Range.getBegin(),
+        "use C++ style comments '//' instead of C style comments '/*...*/'")
+        << FixItHint::CreateRemoval(CharSourceRange::getCharRange(Range));
+
+    return false;
+  }
+
+private:
+  UseCppStyleCommentsCheck &Check;
+  llvm::Regex CStyleCommentMatch;
+};
+
+UseCppStyleCommentsCheck::UseCppStyleCommentsCheck(StringRef Name,
+                                                   ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      Handler(std::make_unique<CStyleCommentHandler>(*this)) {}
+
+void UseCppStyleCommentsCheck::registerPPCallbacks(
+    const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
+  PP->addCommentHandler(Handler.get());
+}
+
+void UseCppStyleCommentsCheck::check(const MatchFinder::MatchResult &Result) {}
+
+UseCppStyleCommentsCheck::~UseCppStyleCommentsCheck() = default;
+} // namespace clang::tidy::modernize
diff --git a/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.h b/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.h
new file mode 100644
index 0000000000000..81b0fdeb018b5
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/UseCppStyleCommentsCheck.h
@@ -0,0 +1,38 @@
+//===--- UseCppStyleCommentsCheck.h - clang-tidy---------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USE_CPP_STYLE_COMMENTS_CHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USE_CPP_STYLE_COMMENTS_CHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::modernize {
+/// detects C-style comments and suggests to use C++ style comments instead
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/modernize/use-cpp-style-comments.html
+class UseCppStyleCommentsCheck : public ClangTidyCheck {
+public:
+  UseCppStyleCommentsCheck(StringRef Name, ClangTidyContext *Context);
+  ~UseCppStyleCommentsCheck() override;
+
+  bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+    return LangOpts.CPlusPlus;
+  }
+
+  void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
+                           Preprocessor *ModuleExpanderPP) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+
+private:
+  class CStyleCommentHandler;
+  std::unique_ptr<CStyleCommentHandler> Handler;
+};
+} // namespace clang::tidy::modernize
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USE_CPP_STYLE_COMMENTS_CHECK_H
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index a23483e6df6d2..95286962f07bb 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -172,6 +172,11 @@ New checks
   Detects variables and functions that can be marked as static or moved into
   an anonymous namespace to enforce internal linkage.
 
+- New :doc:`modernize-use-cpp-style-comments
+  <clang-tidy/checks/modernize/use-cpp-style-comments>` check.
+
+  Find C Style comments and suggests to use C++ style comments instead
+
 - New :doc:`modernize-min-max-use-initializer-list
   <clang-tidy/checks/modernize/min-max-use-initializer-list>` check.
 
diff --git a/clang-tools-extra/docs/clang-tidy/checks/modernize/use-cpp-style-comments.rst b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-cpp-style-comments.rst
new file mode 100644
index 0000000000000..4b2f10420dd97
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-cpp-style-comments.rst
@@ -0,0 +1,12 @@
+.. title:: clang-tidy - modernize-use-cpp-style-comments
+
+modernize-use-cpp-style-comments
+========================
+
+Finds C-style comments and suggests to use C++ style comments `//`.
+
+
+.. code-block:: c++
+
+  memcpy(a, b, sizeof(int) * 5); /* use std::copy_n instead of memcpy */
+  // warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]
\ No newline at end of file
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-cpp-style-comments.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-cpp-style-comments.cpp
new file mode 100644
index 0000000000000..79abf5a53fa2f
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-cpp-style-comments.cpp
@@ -0,0 +1,16 @@
+// RUN: %check_clang_tidy -std=c++11 %s modernize-use-cpp-style-comments %t
+
+static auto PI = 3.14159265; /* value of pi upto 8 decimal places */
+// CHECK-MESSAGES: :[[@LINE-1]]:30: warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]
+
+/******************************************************
+* Fancy  frame comment goes here
+*******************************************************/
+// CHECK-MESSAGES: :[[@LINE-3]]:1: warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]
+
+/** \brief Brief description.
+ *         Brief description continued.
+ *
+ *  Detailed description starts here. (this is a doxygen comment)
+ */
+// CHECK-MESSAGES: :[[@LINE-5]]:1: warning: use C++ style comments '//' instead of C style comments '/*...*/' [modernize-use-cpp-style-comments]

``````````

</details>


https://github.com/llvm/llvm-project/pull/99713


More information about the cfe-commits mailing list